Postgrey crashed, Database lost ?

This morning, the web site was down, certainly due to a ram issue. However, it is now back online.

After the reboot, postgrey, an anti-spam daemon using an automagically filled whitelist database refused to start with the following error in syslog:

ERROR: can’t create DB environment: No such file or directory

I found that the greylisting database in /var/lib/postgrey was corrupted. When I strace postgrey start script with strace -f /etc/init.d/postgrey start I saw misc error messages such as "__db.001: no such file or directory".

After searching the Internet, I found a guy who had the same error and simply destroyed its greylisting berkeley database (sniff, my db ? dead ?). But I didn’t want to loose mine, so I do the following :